The present invention relates to an improved device to aid in holding a vein stable when inserting a needle into the vein for drawing blood or administering drugs.
Veinal blood flow is only towards the heart. Within the veins are leaflet valves which allow blood flow in this direction and stop its reverse flow. When inserting a needle into the vein, typically a tourniquet is positioned on an extremity such as an arm or leg. The veinal blood flow is thereby halted or constricted and the veins on the hand or foot side of the tourniquet begin to swell or distend becoming quite defined and noticeable. Once the desired vein for penetration has been selected, the operator pierces the vein with the needle tip.
The problems encountered with veinal penetration are widely known: the vein may be missed altogether; the needle may completely penetrate through the entire vein; and unsuccessful penetration efforts may injure or damage the vein or surrounding tissue--all to the pain and injury of the patient. After a tourniquet has been applied on an arm, the veins in the extremity become somewhat inflexible. The veins however, still remain measurably resilient to thwart even an experienced operator's attempt at needle insertion. Essentially, any exerted pressure by a needle tip, not longitudinally aligned with a distended vein, may cause the vein to move and resist a piercing attempt.
In the past, known efforts at successful veinal penetration have dealt with using a form of a tourniquet about the arm or leg and some form of an immobilizing means about the vein to be pierced. The operator may attempt to hold the vein between two fingers striving to keep it stationary and thus avoid painful and injurious false efforts in piercing the vein.
Various bulkly and cumbersome instruments have also been utilized in attempting to immobilize the vein for longitudinal needle insertion. U.S. Pat. No. 1,561,116, issued to Silliman on Nov. 10, 1925, is a hand held vein stabilizer for placing over a vein having a flat metal plate including a notch to be directed towards the heart. U.S. Pat. No. 1,824,516, granted to Tyvand on Sept. 22, 1931, is a vein retainer comprising a complex plate structure to be placed over a vein and held there by a tourniquet. U.S. Pat No. 2,103,174, issued to Posada on Dec. 21, 1937, is a surgical instrument having a tourniquet band and a plate, which is attached to the band's end. A central opening is in the plate for retaining a vein. U.S. Pat. No. 3,324,854, granted to Weese on June 13, 1967, is a device to be attached to the barrel of a syringe to stabilize a vein. Such instruments have helped prevent transverse movement of the vein but manifest various limitations in their ease of operation, release and success.